An electrolyte will yield ions by undergoing a:
Select the correct answer below:
- physical change
- chemical change
- spontaneous change
- depends on the substance
The correct answer and explanation is :
The correct answer is chemical change.
Explanation:
An electrolyte is a substance that, when dissolved in water or melted, dissociates into positively charged ions (cations) and negatively charged ions (anions). This process involves a chemical change rather than a physical change. Here’s why:
1. Nature of the change:
- Physical Change: A physical change involves a transformation in the state or appearance of a substance, without altering its chemical structure. For instance, ice melting into water is a physical change because the molecules of water (H₂O) remain intact, though their arrangement changes.
- Chemical Change: A chemical change, however, results in the formation of new substances due to the breaking and forming of chemical bonds. When an electrolyte dissolves in water or melts, it dissociates into ions. For example, when sodium chloride (NaCl) is dissolved in water, it breaks apart into Na⁺ (sodium ion) and Cl⁻ (chloride ion). This dissociation is a chemical change because the ionic bonds in the solid NaCl are broken, and new interactions between the ions and water molecules are formed.
2. Electrolytes and Ion Formation:
Electrolytes, such as salts, acids, and bases, undergo a dissociation reaction in which their ions are separated. This dissociation is a chemical process because it involves the breaking of the chemical bonds that hold the molecules together. For instance, when potassium chloride (KCl) is dissolved in water:
[
\text{KCl (solid)} \rightarrow \text{K}^+ \text{(aq)} + \text{Cl}^- \text{(aq)}
]
This is a chemical change because the ionic bond between K⁺ and Cl⁻ is broken, and the ions interact with the solvent molecules.
3. Spontaneity:
The process of dissociation in electrolytes can be spontaneous or non-spontaneous depending on factors like temperature and solvent. However, the term “spontaneous” does not refer to whether the process is chemical or physical—it describes the thermodynamic favorability of a reaction.
Therefore, when an electrolyte yields ions, it is undergoing a chemical change because the molecular structure is altered, and new chemical species (ions) are formed.